I am using PreComp to get the structural properties of a blade and feed the GH BLADED blade structural inputs.
BLADED requires the bending stiffness about xp and yp
xp and yp are the principal structural axes of stiffness whose origin is the neutral axis or also called in the BLADED theory manual elastic centre. I assume that this point is the same as tension centre in PreComp.
The output file of PreComp “.out_bmd” gives the stiffnesses (flp_stiff, edge_stff and tor_stff) about Xe and Ye that are the principal axes (elastic). These xe and ye have the origin in E that is the shear centre. In Bmodes the shear center E is assumed to be in the chord line.
To feed correctly BLADED i think that I should transform these stiffnesses (flp_stiff, edge_stff and tor_stff) to an axis system parallel to XE - YE but with origin in the tension centre by using the coordinates of the tension centre that PreComp gives in the “.out_gen” file (xt, yt)

Am I ok? or I am misunderstanding the outputs.

Thanks very much and best regards,


Dear Fer,

Did you get any better clarity on this issue.I mean did you figure out about which axis the stiffness calculations are performed in PRECOMP.